FDA saw Viagra, blindness link early

July 1, 2005|By Marc Kaufman, the Washington Post

WASHINGTON -- More than 13 months before a scientific journal reported that Viagra had been linked to a rare form of blindness in some men, a Food and Drug Administration safety officer made the same observation from monitoring adverse event reports and told her supervisors that doctors and patients should be warned of the findings.

Her recommendation was well-received, she told congressional investigators, but nothing happened. The FDA issued no public notice or proposed changes to the Viagra label. That came only after widespread publicity last month about the journal article and public concerns about the possible blindness-Viagra link.

The safety officer's experience was outlined in a letter last week to FDA Acting Commissioner Lester Crawford from Sen. Charles Grassley, R-Iowa, who said the agency had moved far too slowly on an emerging safety concern.

Criticism of the FDA's response to potentially harmful drug side effects has been frequent since Merck & Co. took the painkiller Vioxx off the market last fall after studies indicated it increased the risk of heart attacks and strokes.

"I am troubled by the FDA's action, or lack thereof, relating to the updating of Viagra's product label," Grassley wrote. He said the agency's Office of New Drugs (OND) had done nothing "despite OND's knowledge of the blindness risks since January 2004 and general agreement among FDA staff last spring that the label should be updated."

Researchers remain uncertain whether impotence drugs pose a significant risk of blindness. Drug maker Pfizer Inc. says the side effect has not appeared in Viagra's 103 clinical trials involving 13,000 patients and that the 23 million users have not reported an increased risk of blindness.